Ninja effects?

[Plexistar]

To declare an optional ninja effect, must a player select a target or just declare that their putting that ninja's effect on the stack?

For example, during combat in the exchange of jutsu phase, a player attempts to use Gaara's (us008) effect. At the time of declaration must that player select a target for Gaara's effect to put in on the stack or just announce the activation of it until the time it can resolve?

[Mr Wheat]

for the new rules, you will activate the full effect and put it on the Chain.

the player does nothing within that effect (i.e., selections, discarding, etc.) until that effect is ready to be applied.